Carbamates containing the cycloheptatrien-1-ol-2-one ring



Patented Apr. 13, 1954 CARBAMATES CONTAINING THE CYCLO- HEPTATRIEN-1-OL-2-ONE RING Harold E. Cupery, New Castle County, Del., assignor to E. I. du Pont de Nemours and Company, Wilmington, Del., a corporation of Delaware No Drawing. Application July 13, 1951, Serial No. 236,705

This invention relates to new compositions of matter and to methods for their preparation. More particularly this invention relates to a new class of carbamates containing a seven-membered carbocyclic ring and to a novel process for their preparation.

Compounds containing seven-membered rings occur in several natural products. pounds in general possess valuable properties with respect to regulating plant growth as well as for pesticidal applications. Of particular interest are carbocyclic compounds, especially those containing the cycloheptatrien-l-ol-2-one ring. These compounds have unique chemical properties, e. g., they exhibit many properties which are generally thought of as being primarily associated with aromatic compounds. Cycloheptatrien-l-ol-Z-one (tropolone) has received considerable attention in recent years, since the cycloheptatrien-l-ol-2-one ring exists in certain biolo ically active products, suchas colchicine and fungicides including the thujaplicins which are part of the active portions in cedar wood.

Heretofore, certain carbamates have found use in plant regulant applications. However, no carbamates containing the cycloheptatrien-l-ol-Z- one ring have heretofore been known. New com pounds which contain this vcycloheptatriene ring system and which also contain carbamate groups would have unusual properties, particularly for agricultural use. i

It is an object of this invention to provide new compositions of matter and methods for their preparation. A further object is to provide a new class of compounds containing a seven-membered carbocyclic ring and a process for their preparation. A still further object is to provide a new class of compounds containing the cycloheptatrien-l-ol-Z-one ring and a car'bamate group. Other objects will appear hereinafter.

The objects of this invention are accomplished by providing a new class of carbamates containing the cycloheptatrien-1-ol-2-one ring. the cycloheptatrien-l-ol-2-one carbamates, the halocycloheptatrien-1-ol-2-one carbamates, the nitrocycloheptatrien-l-ol-2-one carbamates and the alkylcycloheptatrien-l-ol-2-0ne carbamates. These novel compounds can be obtained by reacting cycloheptatrien-l-ol-2-one, a halocycloheptatrien-1-ol-2-one. a nitrocycloheptatrien-lol-2-one, or an alkylcycloheptatrien-l-ol-2-one with an isocyanate. The novel carbamates of this invention can also be obtained by reacting a carbamyl chloride with the sodium salt of a cyclobeptetrien-l-ol-zwae compound,

Such com- 11 Claims. (Cl. 260471) A particularly preferred process for the preparation of a product of this invention involves the reaction of cycloheptatfien-l-ol-Z-one or a de rivative thereof which contains groups non-reactive with isocyanates, including those containing halogen, nitro or alkyl substituents on the carbocyclic ring with an organic isocyanate, including aliphatic and aromatic hydrocarbon isocyanates and substituted hydrocarbon isocyanates. Thus new compositions of this invention, such as the cyclo'heptatrien-1-ol-2-one carbamates, have been obtained by the reaction of an organic isocyanate with cycloheptatrien-l-ol- 2-one.

Tropolone, cycloheptatrien-l-ol-2-one, has the structural formula The new carbamates of this invention contain the cycloheptatrien-l-ol-2-one ring and have the general structural formula wherein R is a nuclear substituent including halogen, particularly halogen of atomic number 17 to 35 (i. e., chlorine or bromine) nitro, or alkyl, particularly alkyl of 1 to 3 carbon atoms, n is a positive integer selected from the class consisting of 1 to 2, R1 is a hydrogen or an organic radical and R2 is an organic radical. The organic radicals are generally of not more than 9 chain members selected from the class consisting of carbon, nitrogen and oxygen, particularly hydrocarbon of l to 6 carbon atoms, or alkoxy or halogen substituted hydrocarbons. When n is 1 there is no nuclear substituted R and the structural formula is that of a cycloheptatrien-l-ol- 2-one carbamate which is structurally represented as follows:

wherein R1 and R2 are as aforesaid.

Particularly preierred classes of the new carbamates of this invention are the cycloheptatrien-1-ol-2-one .carbanilates, alkoxycarbanilates and halocarbanilates, the halocycloheptatrien-l- 01-2-0ne carbanilates, alkoxycarbanilates and halocarbanilates, the nititocycloheptatrien-l-ol- 2-one carbanilates, alkoxycarbanilates and halocarbanilates, and the alkylcycloheptatrien-1-01- 2-one carbanilates, alkoxycarbanilates and halocarbam'lates. by the above structural formulas when R2 is phenyl, alkoxyphenyl, particularly where the -alkoxy radical is from 1 to 3 carbon atoms, nitro-- phenyl, or halophenyl, such aschlorophen-yl or bromophenyl.

The most preferred classes of the new carbamates are those where R1 is hydrogen. rand;v

especially the carbanilates where R1 is hydrogen.

The structural formula for the preferred. char,--. 7 banilates where R1 is hydrogen is as follows:

wherein R. is a nuclear substituent selected from the class :consistingof chlorine, bromine, nitroor. alkyl ofl to 3carbon atomsni isaapositive integer of 1 to 2 and R2 is phenyl, bromophenyl, chlorophenyloralkoxyphenyl in which the alkoxy group is of from 1 to 3 carbon atoms.

The following examples in'which theparts are by weight further illustrate this invention.

Example I A mixture of 3.02 parts of 3-bromqqycloheptatrien-l-ol-Z-one (prepared by the process of Cook et al., Chem. and Ind, 1950, 427) and 2.24 parts of p-methoxyphen-yl isocyanate was heated on a steam bath until complete solution resulted and let stand while on the steam bath until solidification occurred. Th solid mass was cooled, triturated with anhydrousether, filtered, and dried. The product obtained. amounted to 4 parts (76% of the theoretical.) :andhada-melting point of 112-l13 C.. The analysis for the p methoxycarbanilate of 3 -bromocycloheptatrien' 1-o1-2-one was:

Calcd. for CI-I12OrNBr: C, 51.42%; H, 3.46%; N, 4.00%. Found: C, 51.63%; H, 3.73%; N, 4.05%.

The carbanilate thus obtained gave no color when dissolved in ether containing a small amount of ferric chloride. The. addition of water to the ether solution resulted in the. slow formation of a green color.

Example II When the general procedure of Example I was repeated except that 4.02 parts of bromocyclo heptatrien-l-ol-Z-one was .employedwith 1.42 parts of ethyl isocyanate, there was obtained. 35 parts of the corresponding ethylcarbamate of S-bromocycloheptatrien-l-ol-2-one. The product had a melting point of 99100 C. and the following analysis:

Calcd. for CioHioOsNBl! C, 44.13%; H, 3.70%; N, 5.15%. Found: C, 44.28%; H, 3.82%; N, 5.07%.

Example III When 1.22 parts of cycloheptatrien-l-ol-2-one obtained by the process of Cook et al., Chem. and Ind... 1950, 427, was mixed with 1.19 parts of phenyl isocyanate a clear solution was obtained.

- Thetemperature of this solution .rose to 45?:(2.

These carhanilates arerepresented.

of 'p-chlorophenyl. isocyanate, there was obtained 4 parts (corresponding to a 74% yield) of the p-chlorocarbanilate of cycloheptatrien-l-ol-Z- one. The compound had a melting point of 1*35-13'6.5 C. and the following analysis:

Caldd. for C14H10O3NC12 C, 60.99%; H, 3.66%; N, 5.08%. Found: C, 60.91%; H, 3.83%; N, 5.07

Example V" When the general. procedure of Example was repeated except that the isocyanate employed was L68 parts of adipyl, isocyanate, there was obtained 2.5 parts (correspondingto a 61% yield) of the corresponding .carbamate, the N-(G-isocyanatohexyl) carbamate of cycloheptatrien-l-ol-Z-one. The product had. a melting point of SB-88 C. and the analysis ,for'the com;

pound having the structure.

N, 9.65%. Found; C; 62.46%; H, 6.73% .N, 9.47%. 1

In the place of the cycloheptatrien-1-ol-2-one. as employed in the latterexamples, other nuclear substitution products that contain as thesole Calc d. for censoring: c, 62.05%; H, 6.251%:

active hydrogen (Zerewitinoff) theuhydroxylhydrogen, can be used. The most suitable and preferred .are .thosewhich contain an lalkyl. of 1 to..3.ca-rhons,..e. -g.,..as'in hinokitiol. or thuilaplicin, a .nitm, e. g., as in 5.-nitro.cynloheptatrien1- l-o1-2-one, or a halogen, particularly. bromine. or

chlorine, assubstituents on the. carhocyclic ring. In place of the visocyanates of the examples,

other isocyanates that. are equally useful include. 1 alpha naphthylisocyanate, ,o nitrophenylisoe cyanate and o phenylphenylisocyanate. Compounds coming within the scopeof this inven: tion also include the N.-.(-.alpha-.naphthyl) carbamate of 5-isopropylcycloheptatrien-l -olg2- one, the o-nitrocarbanilate :of 3.,4.-hen-zoc-y.cloheptatrien-l-ol-z-one, and. the Q-phenyICarbani-Iate of .5-nitrocycloheptatrienlol-2,-one.

The examples illustrate the preparation of the I compounds of this invention by the use. of ,isu-

cyanates. :Carbamates havebeen prepared. by

other methods which can optionally. he employed in the preparationof. thecycloheptatriene carbamates :ofthis invention- .A' suitable. method; in: volves the reaction of ..a carbamyl. chloride with.

the sodium salt of .a .cyclohptatrieml-ole2eone; The exact .conditionsnfor :the carhamatefnrming reaction depend upon the-specificireagent employed. Temperatures of 20-125 .C; or higher. are useful. Satisfactory yields aregeneraliyxobtained at temperatures of about-1009 0...wheniithe.

time of reaction is 1-10 hours. The molar ratio of carbamate forming reagent, e. g., the isocyanate, present should be at least as high as the ratio on a molar basis of the carbocyclic compound present.

The carbamates of this invention can be employed in the formulation of biologically active products. The carbamate group is susceptible to hydrolysis under selected conditions and the compounds may be used as chemical intermediates. These derivatives differ in stability from the parent cycloheptatrien-lo1-2ones. The carbamates of this invention are of particular use in the formulation of pesticidal, fungicidal, or plant regulant materials.

As many apparently widely different embodiments of this invention may be made without departing from the spirit and scope thereof, it is to be understood that this invention is not limited to the specific embodiments thereof except as defined in the appended claims.

I claim:

1. A carbamate containing the cycloheptatrien- 1-01-2-one ring and having the general formula:

wherein R is selected from the class consisting of halogen .of atomic number 17 to 35, the nitro group, the benzo radical, and alkyl radicals of 1 to 3 carbon atoms, n is a positive integer of 1 to 2, and R2 is selected from the class consisting of alkyl radicals of 1 to 6 carbon atoms, alkoxyphenyl in which the alkoxy group is of 1 to 3 carbon atoms, phenyl, biphenyl, monohalophenyl, nitrophenyl, naphthyl, and isocyanato substituted alkyl radicals containing a total of not more than 7 carbon atoms.

2. A carbamate containing the cycloheptatrien-1-ol-2-one ring and having the general formula:

wherein R is bromine, n is a positive integer of 1 to 2, and R2 is an alkoxyphenyl radical in which the alkoxy group contains from 1 to 3 carbon atoms.

3. A carbamate containing the cycloheptatrien-I-ol-Z-one ring and having the general formula:

wherein R is bromine, n is a positive integer of 1 to 2, and R2 is an alkyl radical of 1 to 6 carbon atoms.

4. A carbamate containing the cycloheptatrien-l-ol-z-one ring and having the general formula:

(RM-1 wherein R is bromine, n is a positive integer of l to 2, and R2 is phenyl.

5. A carbamate containing the cycloheptatrien-l-ol-Z-one ring and having the general formula:

\ iii h-1 wherein R is bromine, n is a positive integer of 1 to 2, and R2 is chlorophenyl.

6. A carbamate containnig the cycloheptatrien-l-ol-Z-one ring and having the general formula:

No references cited. 

1. A CARBAMATE CONTAINING THE CYCLOHEPTATRIEN1-OL-2-ONE RING AND HAVING THE GENERAL FORMULA: 